A liquid crystal panel used in a liquid crystal display device such as a liquid crystal television, for example, does not emit light, and thus, it is necessary to provide a separate backlight device as an illumination device.
Patent Document 1 discloses a configuration of a backlight device that includes: a chassis (backlight shield) that has a side thereof facing a liquid crystal panel open; a light source stored in the chassis; a plurality of optical members (optical sheets for a liquid crystal panel) disposed so as to cover the opening of the chassis; and a clamping member made of a bezel and the chassis and clamping the optical members. Each of the optical members disclosed in Patent Document 1 has elastic protrusions on the outer edges thereof such that the stacked plurality of optical members are elastically held in place in the backlight device, thereby making it possible to absorb the thermal expansion of the optical members.